For your ears only: The Logitech UE Personal Reference Monitors

The Logitech Ultimate Ears Personal Reference Monitors are truly bespoke audio, hand crafted just for you. They'll fit your ears only, the sound is your sound, with a tonal balance tweaked by you, for you. Accuracy isn't part of the PRMs raison d'etre, not in the slightest, it's pure audio self-indulgence. That level of customization doesn't come cheap, the PRM is $1,999!

If accuracy is what you crave, save $1,000 and buy the Ultimate Ears' superb Reference Monitor ($999), it's more neutral than any IEM I've heard to date. The PRM isn't accurate, and that's why I love it, it's a three-way, balanced armature driver, custom-molded to your ears in-ear monitor. There are two bass drivers, two midranges and one tweeter driver; when each PRM is manufactured the crossovers are adjusted to suit the owner's sonic preferences. Available finishes include Cherry, Walnut Burl, Carpathian Elm Burl and Purple Heart.

Up Close and Personal
To get started on the review I visited audiologist Dr. Julie Glick's Manhattan office to have her make "impressions" of my ear canals, and I dialed in my sound with Ultimate Ears' three-band Personal Reference Tuning EQ Box. The tuning range is variable and interactive based on the EQ choices made by the user, and the range of adjustment is roughly +/- 7dB for the bass, midrange, and treble settings. There are a total of six EQ knobs on the tuning box for the left and right channel controls (the frequency ranges of the controls aren't specified by UE). The universal fit PRM headphones I used to set the EQ sounded all round better than standard Reference Monitors, even before I diddled the EQ controls (UE doesn't sell this universal fit model, it's only used to help customers preview the EQ-ed sound).


Ultimate Ears' three-band Personal Reference Tuning EQ Box allows you to independently adjust the bass, mid-range, and treble for the left and right ear.

I used my iPod Classic as a music source, and started by focusing on the sound of male and female voices. It's easy to instantly return to the flat setting with a push of a button on the Tuning EQ Box, and that really helps keep the changes in perspective. I listened to a bunch of audiophile Chesky recordings, and since I was present at the sessions I had a handle on what they should sound like. I also used a lot of classic, analog era acoustic rock and jazz albums I've heard on countless systems, and new electric rock recordings including the latest Grizzly Bear CD, "Shields," and Jack White's recent solo effort, "Blunderbuss." Most newer albums are more dynamically compressed and have brighter tonal balances than pre- 1990s recordings. Sadly, few new recordings sound natural or unprocessed, so listening to them on super accurate headphones is a sonic assault of the worst kind. My goal with most new recordings is to try to make them sound good, without forfeiting too much of what I liked about the sound of the audiophile recordings. Dialing in the sound is a balancing act of sorts. I listened to the PRMs at low, medium and loud levels, because volume definitely affects perceived tonal balance. Two weeks after my tuning session the headphones arrived, packed in UE's little road case, cute! The PRM comes with a 48 inch long braided, user replaceable cable, but UE also offers a 64 inch cable for $30.

Each PRM is hand made at UE's Irvine, California facility, where they produce all UE custom molded models, which start with the $399 UE 4. The Personal Reference Monitor is the only model that can have its frequency response custom tuned, and that service is only available from selected audiologists that work with UE and have the tuning EQ box. For now they are only in NYC, Nashville, Austin, and Irvine (there are plans for more locations, including cities in Germany, U.K., and the Netherlands). UE will also have an audiologist and a tuning box at this year's Head-Fi CanJam at the Rocky Mountain Audio Fest in Denver in October.

I spend a lot of time thinking about sound, but I was a little intimidated by the process of locking in my PRMs' sound, what if I got it wrong? What if I hated the sound? I didn't, I loved it, but what about the real paying customers? What if they're unhappy with the result? UE's Director of Sales Chuck Reynolds assures me that UE will do everything they can to make the customer happy, and will make new headphones with different EQ curves if need be. Same goes for the fit, if the in-ear fit isn't perfect, UE will make it right. The PRM is a luxury product and UE wants happy customers.

Let's see how they turned out ...

Logitech Ultimate Ears
3 Jenner Street, Suite 180
Irvine, CA 92618
(800) 589 6531

Bennyboy's picture

That UE box looks just like the 'stress test' machines that Scientologists lure innocent punters in with. Does a good job of equalising your wallet out, I bet.

I don't get it - $2k just so you can get coloured sounding customs?  Weird. What happens when you get a new player with a different sound signature? Or play different types of music? Or go into the real world with them, where there's noise and rumbly stuff that changes how you hear sound? 

So, neutral is now just soooo 2011 is it, darhling? Plus ca change, as they say on the catwalks of Paris.....

Seems like a massively overpriced, gimmicky faff to me.

Perfectly pitched for the high-end audiophile market then.....

Steve Guttenberg's picture



ALL headphones are colored, just in different ways. If they weren't, they would all sound more similar than they do. Cool, as I said about the PRMs, save $1,000 and get the Reference Monitor for accuracy. That's easy.

Jlle's picture

Just wondering I've you have every compared it to the new Aurisonic AS2? (AS1 needs high EQ).

Steve Guttenberg's picture

Sorry, no.

AstralStorm's picture

I bet the UE PRM setup allows you personal tuning of crossover frequencies and driver gain.

Pity that's no replacement for actual equalization, but should make it far less necessary.

Yousho421's picture

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